New lenses? Great. Just when I gave up and bought two FD lenses! I've been using the FD 50mm 1.4 and it actually doesn't look all that big on the M. It's a little front heavy but I like the weight and you can grip it better with your left hand cradling the lens.
I also bought an FD 100mm 2.8, just waiting for it to arrive.
Since we already have a wide angle zoom and general purpose zoom it stands to reason we'll see a tele zoom for the M. That would be very interesting. Perhaps a prime to go along with it? I hope it has IS as the M really needs it.
This is promising news for the M series, I'm glad Canon haven't decided to scrap it totally.
ANY camera held at arm's length would need IS - that's one MAJOR advantage with an eye level viewfinder - it becomes a three point brace (head, left hand and right hand all braced against the bod) and the camera can be cradled in the left hand worth at least 2 stops.
People (at least this people) would want something larger than than a FB or any social media post - that's where the big sensor comes into play. The bigger the blowup, the steadier the camera needs to be (and still be sharp)
Canon has already made the decision not to follow other maker's lead with in-camera IS. I think that's apparent in the lenses coming out, mostly all with IS in the lens.
Same thing for the FF dreamers - Canon has designed these lenses with the image circle to cover the APS-C sensor, not FF. Don't count on yet another line of canon lenses in this mount with the image circle large enough for FF.
Bracing the camera is fact. Of course, the last two points is me reading the tea leaves - YMMV.